Reeskers wrote:
I just spent $90 to purchase a Thunderbolt 2 cable plus a Thunderbolt 3 to Thunderbolt 2 adaptor to connect my MacBook Air 2017 to my new Dell P2721 monitor, and it doesn't work. Ideas? Troubleshooting? Novice here, so any advice or tips are appreciated. Thank you.
You are not going to want to hear this, but you bought the wrong cabling and adapters.
Based on the specs on this page:
https://www.dell.com/en-us/work/shop/dell-27-4k-usb-c-monitor-p2721q/apd/210-axlt/monitors-monitor-accessories
your display has:
Input Connectors
1 x HDMI port version 2.0
1 x DisplayPort version 1.2
2 x High-Speed USB 2.0 downstream ports
2 x USB 3.2 Gen1 (5 Gbps) downstream ports
1 x USB Type-C (Alternate mode with DisplayPort 1.2, USB 3.2 Gen1 (5 Gbps) upstream port, Power Delivery PD up to 65 W)
The 2017 has:
- Two USB 3 ports (up to 5 Gbps)
- Thunderbolt 2 port (up to 20 Gbps)
What you need is one of the following:
-MiniDisplay Port to DisplayPort cable
-MiniDisplay Port to HDMI
The 2017 does not support video on the USB ports. You can however, use a USB-A to USB-C cable to allow you access to the USB hub in the display.
Bottomline, you cannot make a single connection to your display nor utilize its power delivery functions.
Also, for the video connection, purchase only certified cables which will save possible issues.